Apparatus and process for washing drying and sterilising industrial plants

ABSTRACT

A water tank is connected through a high-pressure feed line to one or more washing terminals associated to a surface to be treated. An ozoniser removes oxygen from a tank and transforms it into ozone, which is conveyed to the tank where it is mixed with the water. The ozone is then conveyed to a drying line which takes drying air from the atmosphere and sends it to the surfaces to be treated. The ozone mixes with the drying air, forming a mix which strikes the surfaces of the plant, drying and sterilising them. A secondary sterilising line selectively places the tank in closed-circuit communication with some parts which during normal operation are not crossed by the washing liquid. The invention is particularly suited to the pharmaceutical industry, and enables efficient sterilisation of treated surfaces even where they are not directly contacted by the liquid sprayed from the washing terminals.

TECHNICAL FIELD

The invention relates to the field of apparatus and methods for washingand sterilising industrial plants.

BACKGROUND ART

Especially, though not exclusively, the invention is usefully applied inplants in the pharmaceutical industry, such as for example granulation,mixing, dissolving,

U.S. Pat. No. 5,329,950 discloses a self-containing cleanig andsanitizing equipment which includes: a first liquid holding tank for acleaning solution, a second liquid holding tank for a sanitizingsolution, a cleaning line running from the first tank and a sanitizingline running from the second tank. A sterilizing gas is introduced inthe sanitizing line.

The main aim of the present invention is to provide an especiallyefficient process for automatic washing, drying and sterilising of thetreated surfaces of an industrial plant.

An advantage is that even the parts which do not come into directcontact with the washing liquid spraying the plant during cleaningoperations are fully sterilised.

A further aim is to provide a simple and economical apparatus forrealising the above-cited process.

A further aim of the invention is simply and practically to sterilisethe apparatus using cold fluids.

These aims and advantages and others besides are all attained by theinvention as it is characterised in the appended claims.

DISCLOSURE OF INVENTION

Further characteristics and advantages of the present invention willbetter emerge from the detailed description that follows of a preferredbut non-exclusive embodiment of the invention, illustrated purely by wayof a non-limiting example in the accompanying FIGURE of the drawing, inwhich:

FIG. 1 is a diagram of an apparatus realised according to the invention.

With reference to the FIGURE of the drawing, 1 denotes in its entirety aplant comprising two combined apparatus which cooperate with oneanother. A first apparatus is for drying and sterilising industrialplants and a second apparatus is for washing industrial plants.

The apparatus comprises a tank 2 containing a washing liquid (forexample, water) connected, through a high-pressure feed line 3comprising a pipe including a pump 4 (for example a high-pressure pump),to one or more washing terminals 5 (for example water wand-type nozzles)which are associated with the surfaces of the plant which are to betreated. In the illustrated embodiment there is also a batcher 6 whichfeeds the line 3 with measured amounts of a detergent at a pointupstream of the pump 4.

A short line 7 is attached to the tank 2, which will join up with anexternal line supplying the washing fluid, for example the municipalwater supply. A further short line 8, also removably connectable to thewater supply, joins the high-pressure feed line 3 at a three-way switchvalve 9 predisposed (upstream of the high-pressure pump and at anon-pressurised point) selectively to connect the high-pressure feedline 3 with the tank supply 2 or with the municipal water supply throughthe connecting line 8. Both short connecting lines 7 and 8 are providedwith an intercept valve.

The apparatus 1 comprises means for introducing a sterilising gas intothe tank 2, which gas mixes with the washing liquid. The means forintroducing the sterilising gas comprise a gas feed line which includesan ozoniser 10 (provided with a high-voltage generator). The ozoniser 10takes oxygen from a tank 11 and transforms it into ozone. Any fixedsupply line of oxygen can be used. The oxygen supply line terminatesinside the tank 2 with an injector 12 located close to the bottom of thetank 2 which releases the ozone (a sterilising gas) into the washingliquid, thus obtaining a mixture of the two substances.

The apparatus comprises a secondary automatic sterilising line 13predisposed to connect selectively the tank 2 with parts of theapparatus which during normal functioning are not crossed by the washingliquid, so that these parts too can be sterilised. In the illustratedembodiment these non-contact parts are the two short water lines 7 and 8which supply the washing liquid (water) to the tank, and thehigh-pressure feed line 3. During automatic sterilisation the ends ofthe short lines 7 and 8 are detached from the municipal water supply andjoined up to the secondary automatic sterilising line 13. The secondaryline 13 exhibits at one end a removable and selective connection withthe short lines 7 and 8; while at its other end it exhibits a connectorfor selective and removable connection with a subsidiary draining line14 of the tank 2, provided with a draining pump 15, which can on demandbe used both for draining liquid remaining in the tank 2 and forautomatic sterilisation of parts of the apparatus.

The drying apparatus comprises a drying line 16 predisposed to supply adrying gas to the treated surfaces of the industrial plant (of knowntype and not illustrated).

The drying line 16 is connected through a three-way switch valve 17 tothe feed line which introduces the sterilising gas into the tank; thisconnection enables the sterilising gas—ozone—to be mixed with the dryinggas—air. The drying line 16 is provided with a feed line which removesair from the atmosphere; along the feed line means for moving the airare arranged (for example an aspirating fan), a heater 19 and a filter20.

The drying gas is sent towards the plant to be dried in the direction ofarrow G. The drying line 16 is connected through a conduit and a valve17 to a gas feed line on which an ozonizer 10 (provided with a voltagegenerator) is provided. The ozoniser 10 takes oxygen from a tank 11 andtransforms it into ozone. Any fixed supply line of oxygen can be used.In the illustrated embodiment the valve is a three-way switch valve 17to the feed line which introduces the sterilising gas into at least oneuser (in this embodiment the second washing apparatus, as will be betterexplained herein below), as well as enabling the sterilising gas—ozone—to be mixed with the drying gas—air before the mixture is sent on tothe surfaces to be treated. Predisposing at least one further user foruse with the sterilising gas supply is optional, preferable but notnecessary.

The drying line 16, like the short lines and 8, is associated to asecondary recycling line 21 which is selectively connectable to thedrying line 16, to create a closed automatic sterilising circuit of thedrying line 16. The secondary recycling line 21 is basically a by-passfor performing, when so desired, an automatic sterilisation of thedrying line 16.

The various above-mentioned parts of the apparatus 1—in particular thetank 2, the high-pressure feed line 3, the pump 4, the washing terminals5 and the means for introducing sterilising gas, but also the dryingsystem as well as the auto-sterilising systems with ozonised water andozonised air—are mounted on a mobile washing unit with wheels (notillustrated).

The apparatus enables automatic sterilisation and cleaning of structuralcomponents with no need to dismount them: this is realised by means ofthe on-site production of sterilising gas (ozone) which is mixed withthe washing liquid and thus conveyed at low temperature to the inside ofthe hydraulic circuit of the apparatus. The same solution is applied tothe pneumatic drying circuit, with the difference that the sterilisinggas is mixed with the drying gas. This solution means that the samecontrol unit can be programmed to command both the washing/dryingoperations and the automatic sterilising cycle.

Cold automatic sterilising (instead of, for example, sterilising usingheated steam) of the washing and drying apparatus means thatrelatively-cheap parts of the apparatus itself can be used in theoperation, as no compatibility with high temperatures is required.

Production and introduction of sterilising gas into the tank 2 and thepneumatic circuit are controlled (using known techniques) so that thesaturation level of sterilising gas (in this embodiment ozone) mixedwith the washing liquid (in this case water) or in the drying fluid (inthis case air) is never exceeded, so no over-production of ozoneobtains.

It has been seen that by using a high-pressure washing liquid and amixed-in sterilising gas (i.e. in the present embodiment ozonised water)an extremely efficient wash and sterilisation is obtained of all of thetreated surfaces of the plant. In the case of ozonised water,high-pressure delivery over the surfaces to be treated accelerates thetransformation of the ozone contained in the water into active oxygen,which is able to sterilise even those parts of the machine which are notdirectly sprayed by the jets of pressurised liquids.

The invention has the advantage of concentrating the washing, the dryingand sterilising operations in a single compact apparatus which isself-sufficient and mobile in that it can be mounted on wheels. It alsoenables a final printing of a single non-changeable report to be made ofall the washing, drying and sterilisation process.

The invention also consists in the actuation of a drying and sterilisingprocess for industrial plants in which a drying gas is taken from asource, for example the atmosphere, and sent through one or moreconduits twoars at least one surface of a plant to be dried andsterilised, which is struck by the drying gas flow. The processintroduces a sterilising gas into the conduits, which is mixed with thedrying gas.

The drying gas comprises ozone.

The process, which is preferably performed by an apparatus such as theone described, automatically sterilises a part of the apparatus with thedrying gas flow in a closed circuit.

1.-21. (cancelled)
 22. An apparatus for washing and sterilisingindustrial plants, comprising at least one tank (2) for a washing liquidconnected, through at least one high-pressure feed line (3) equippedwith at least one pump (4), to at least one washing terminal (5) whichis associated to a surface to be treated, characterized in that itcomprises means (10, 11, 12) for introducing a sterilising gas into thetank (2), which sterilising gas mixes with the washing liquid in thetank.
 23. The apparatus of claim 22, characterized in that the means forintroducing the sterilising gas comprise an ozoniser (10) which removesoxygen from a tank (11) and transforms the oxygen into ozone, which isconveyed to the tank (2).
 24. The apparatus of claim 22, characterizedin that it comprises at least one secondary line for automaticsterilisation (13) which can selectively place in a closed-circuitcommunication the tank (2) with parts of the apparatus which duringnormal functioning are not crossed by the washing liquid, in order thatthe parts of the apparatus which during normal functioning are notcrossed by the washing liquid can be washed.
 25. The apparatus of claim24, characterized in that the parts of the apparatus which areautomatically sterilised comprise one or more short lines (7 and 8) forsupplying a washing liquid to the tank (2) and the high-pressure feedline (3), each of the short lines (7 and 8) being provided with at leastone end which can be attached to an external supply source.
 26. Theapparatus of claim 22, characterized in that it comprises a drying line(16) for supply a gaseous drying fluid to treated surfaces, which dryingline (16) is connected to means for introducing sterilising gases formixing the sterilising gas with the gaseous drying fluid.
 27. Theapparatus of claim 26, comprising a secondary line (21) for recycling,selectively connected to the drying line in order to realize asterilising closed circuit of the drying line (16).
 28. The apparatus ofclaim 22, characterized in that at least the tank (2), the high-pressurefeed line (3), the pump (4), the washing terminal (5) and the means (10,11, 12) for introducing the sterilising gas are mounted on a compactwashing unit which is self-sufficient and mobile on wheels.
 29. (new)the apparatus of claim 26, characterized in that the means forintroducing the sterilising gas comprise an ozoniser (10) which removesoxygen from a tank (11) and transforms the oxygen into ozone, which isconveyed to the drying line (16).
 30. The apparatus of claim 22,characterized in that it comprises at least one secondary line forautomatic sterilisation (13) which can selectively place in aclosed-circuit communication the tank (2) with parts of the apparatuswhich during normal functioning are not crossed by the washing liquid,in order that the parts of the apparatus which during normal functioningare not crossed by the washing liquid can be washed.
 31. The apparatusof claim 22, charactersied in that at least the tank (2), thehigh-pressure feed line (3), the pump (4), the washing terminal (5) andthe means (10, 11, 12) for introducing the sterilising gas are mountedon a compact washing unit which is self-sufficient and mobile on wheels.32. A process for washing and sterilising industrial plants wherein awashing liquid is sourced from a tank (2), is pumped and sent at highpressure toward at least one washing terminal (5) which directs thewashing liquid to a washing and sterilising plant, characterized in thatit injects a sterilising gas internally of the tank (2), whichsterilising gas mixes with the washing liquid.
 33. The process of claim32, characterized in that the sterilising gas comprises ozone.
 34. Theprocess of claim 32, characterized in that, after washing, surfaces ofthe plant are sprayed with a drying flow of gas containing thesterilising gas.
 35. The process of claim 32, characterized in that theprocess is realized by an apparatus which is automatically sterilised bythe closed-circuit drying flow of gas.
 36. The process of claim 32,characterized in that the process automatically washes and automaticallysterilises, in a closed circuit and uses the washing liquid sourced fromthe tank (2), at least a part of the apparatus, especially theconnections for connecting the tank (2) and the high-pressure feed line(3) with an external source of the washing liquid.